I noticed that a part of the code was missing after this commit, so I reverted this one and committed the changes again after pulling in another commit first. By then everything was in, including $to.removeClass( toPreClass ).

Anyway, these changes have been removed by commit 8e570e3. So the answer is no, this is not in 1.1.1.. This means no toPreClass is being added and shouldn't have to be removed.

When you say "I was getting nothing showing up, but removing the pre-class fixed it.", are you talking about 1.1.1. final?

People that want to use the fix that was accidently removed can replace the startIn function in 1.1.1. final by the code shown below.
The declaration of the variable toPreClass was still in the 1.1.1. final code as well as the CSS for class ui-page-pre-in.